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Quantitative ultrasound (QUS) aims to find properties of scatterers which are related to the tissue microstructure. Among different QUS parameters, scatterer number density has been found to be a reliable biomarker for detecting different…

Signal Processing · Electrical Eng. & Systems 2023-02-28 Ali K. Z. Tehrani , Ivan M. Rosado-Mendez , Hayley Whitson , Hassan Rivaz

We describe a novel end-to-end approach using Machine Learning to reconstruct the power spectrum of cosmological density perturbations at high redshift from observed quasar spectra. State-of-the-art cosmological simulations of structure…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-21 Maria Han Veiga , Xi Meng , Oleg Y. Gnedin , Nickolay Y. Gnedin , Xun Huan

K-means clustering, a classic and widely-used clustering technique, is known to exhibit suboptimal performance when applied to non-linearly separable data. Numerous adjustments and modifications have been proposed to address this issue,…

Methodology · Statistics 2026-04-07 Zhili Qiao , Wangqian Ju , Peng Liu

We combine K-means clustering with the least-squares kernel classification method. K-means clustering is used to extract a set of representative vectors for each class. The least-squares kernel method uses these representative vectors as a…

Machine Learning · Computer Science 2020-12-25 M. Andrecut

One of the most popular algorithms for clustering in Euclidean space is the $k$-means algorithm; $k$-means is difficult to analyze mathematically, and few theoretical guarantees are known about it, particularly when the data is {\em…

Machine Learning · Computer Science 2009-12-02 Kamalika Chaudhuri , Sanjoy Dasgupta , Andrea Vattani

The $k$-means clustering algorithm and its variant, the spherical $k$-means clustering, are among the most important and popular methods in unsupervised learning and pattern detection. In this paper, we explore how the spherical $k$-means…

Methodology · Statistics 2019-05-28 Anja Janßen , Phyllis Wan

K-means (MacQueen, 1967) [1] is one of the simplest unsupervised learning algorithms that solve the well-known clustering problem. The procedure follows a simple and easy way to classify a given data set to a predefined, say K number of…

Machine Learning · Computer Science 2017-06-23 Srikanta Kolay , Kumar Sankar Ray , Abhoy Chand Mondal

We study large-scale UV background inhomogeneity in three-dimensions associated with the observed quasar populations at high redshift. We do this by measuring metal absorption through quasar absorption spectrum stacking as a function…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-18 Sean Morrison , Matthew M. Pieri , Debopam Som , Ignasi Pérez-Ràfols

Structural regularities in man-made environments reflect in the distribution of their surface normals. Describing these surface normal distributions is important in many computer vision applications, such as scene understanding, plane…

Computer Vision and Pattern Recognition · Computer Science 2016-11-15 Julian Straub , Trevor Campbell , Jonathan P. How , John W. Fisher

Kernel $k$-means clustering is a powerful tool for unsupervised learning of non-linearly separable data. Since the earliest attempts, researchers have noted that such algorithms often become trapped by local minima arising from…

Machine Learning · Statistics 2020-11-13 Debolina Paul , Saptarshi Chakraborty , Swagatam Das , Jason Xu

In this work, the possibility of clustering correlated random variables was examined, both because of their mutual similarity and because of their similarity to the principal components. The k-means algorithm and spectral algorithms were…

Machine Learning · Computer Science 2019-09-10 Zenon Gniazdowski , Dawid Kaliszewski

In order to obtain morphological information of unlabeled galaxies, we present an unsupervised machine-learning (UML) method for morphological classification of galaxies, which can be summarized as two aspects: (1) the methodology of…

Astrophysics of Galaxies · Physics 2022-02-02 C. C. Zhou , Y. Z. Gu , G. W. Fang , Z. S. Lin

Clustering analysis is one of the most widely used statistical tools in many emerging areas such as microarray data analysis. For microarray and other high-dimensional data, the presence of many noise variables may mask underlying…

Machine Learning · Statistics 2008-03-26 Benhuai Xie , Wei Pan , Xiaotong Shen

This paper presents a novel method for clustering surfaces. The proposal involves first using basis functions in a tensor product to smooth the data and thus reduce the dimension to a finite number of coefficients, and then using these…

Methodology · Statistics 2021-02-04 Adriano Zanin Zambom , Qing Wang , Ronaldo Dias

Clustering is a fundamental task for analyzing unlabeled data based solely on its underlying distribution. Spectral clustering is a clustering method that represents a dataset as a graph and uses the relationships between data points.…

Quantum Physics · Physics 2025-04-01 Hyeong-Gyu Kim , Siheon Park , June-Koo Kevin Rhee

Clustering is a popular form of unsupervised learning for geometric data. Unfortunately, many clustering algorithms lead to cluster assignments that are hard to explain, partially because they depend on all the features of the data in a…

Machine Learning · Computer Science 2020-09-23 Sanjoy Dasgupta , Nave Frost , Michal Moshkovitz , Cyrus Rashtchian

Gene expression profiles are essential in identifying different cancer phenotypes. Clustering gene expression datasets can provide accurate identification of cancerous cell lines, but this task is challenging due to the small sample size…

Biological Physics · Physics 2023-05-30 Yuchen Wu , Luke Dicks , David J. Wales

The immense amount of time series data produced by astronomical surveys has called for the use of machine learning algorithms to discover and classify several million celestial sources. In the case of variable stars, supervised learning…

Solar and Stellar Astrophysics · Physics 2022-10-12 R. Pantoja , M. Catelan , K. Pichara , P. Protopapas

In this paper, we build autoencoders to learn a latent space from unlabeled image datasets obtained from the Mars rover. Then, once the latent feature space has been learnt, we use k-means to cluster the data. We test the performance of the…

Instrumentation and Methods for Astrophysics · Physics 2019-11-18 Vikas Ramachandra

Industrial process monitoring increasingly relies on sensor-generated time-series data, yet the lack of labels, high variability, and operational noise make it difficult to extract meaningful patterns using conventional methods. Existing…

Machine Learning · Computer Science 2025-11-18 Zhipeng Ma , Bo Nørregaard Jørgensen , Zheng Grace Ma
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